1. Field of the Industrial Application
This invention relates to a compressor in which a compression element with a refrigerant suction opening is built in a casing, a connecting opening is formed in the casing at the position corresponding to the position of the refrigerant suction opening, and a refrigerant pipe is connected to the refrigerant suction opening of the compression element through an inlet tube inserted into the connecting opening, and to a method of manufacturing the compressor.
2. Description of the Prior Art
A compressor of this type, in which the refrigerant pipe is connected to the refrigerant suction opening of the compression element built in the casing, has been disclosed, for instance, by Japanese Utility Patent Application (OPI) No. 74587/1990 (the term "OPI" as used herein means an "unexamined published application"), and is as shown in FIG. 3. In the compressor, a coupling pipe B and an inlet tube F are used. The coupling pipe B is connected to a connecting opening C1 formed in the casing C by brazing. The inlet tube F is loosely inserted into the coupling pipe B, and then the end portion of the inlet tube F is press-fitted into a refrigerant suction opening A of a compression element CP which is incorporated in the casing C. Under this condition, the coupling pipe B is welded to the inlet tube F by brazing, and the inlet tube F is also welded to a refrigerant pipe D by brazing which is inserted into the inlet tube F.
The compression element CP is built in the casing C by coupling it to an electric motor M which is secured therein by shrinkage fitting, and it is secured to the casing C by spot-welding, with the inlet tube F connected to the refrigerant pipe D and to the coupling pipe B by brazing.
As was described above, the conventional compressor employs the coupling pipe B. The coupling pipe B must be fixedly secured to the connecting opening C1 of the casing C by welding. In welding the coupling pipe B with the compression element CP set in the casing, it is necessary to take thermal effects into account. In securing the compression element CP to the casing C by spot welding, before the inlet tube F is welded to the coupling pipe B the compression element CP is positioned in place, and a predetermined air gap E is set between the rotor RT and the stator ST of the motor. In this operation, the inlet tube F is inserted into the coupling pipe B with a gap therebetween, and therefore the compression element CP is liable to be displaced with respect to the casing C. As a result, the air gap E between the stator ST and the rotor RT of the motor M is changed; that is, it is difficult to maintain the air gap E unchanged.